Surface optimization of Ti6Al4V alloy with hydroxyapatite and iron oxide nanoparticle coatings for biomedical applications

Due to the increasing demand for materials that integrate strong mechanical performance with biological activity, surface modification of Ti6Al4V alloys has emerged as a pivotal strategy for enhancing osseointegration. This study investigates the surface functionalization of biomedical Ti6Al4V through the deposition of hydroxyapatite (HAp) and iron oxide nanoparticles (Fe 3 O 4 ) via immersion in simulated body fluid (SBF). Morphological and physicochemical characterizations were conducted using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD), Raman spectroscopy, and contact angle measurements. Biological performance was rigorously assessed through viability, irritability, and angiogenic assays, including Calcein-AM fluorescence, agar hemolysis, and the Hen's egg test on chorioallantoic membrane (HET-CAM). Results demonstrated effective and uniform deposition, leading to significant structural transformations on the alloy surfaces for both HAp and HAp/Fe 3 O 4 groups. These modifications established hydrophilic interfaces with high interfacial free energy of adhesion (∆FAdh = −21.9 mJ/m 2 ), exceeding the critical energy threshold required for protein adsorption and subsequent cellular adhesion. Biological assays confirmed hemocompatibility and a lack of cytotoxicity. Furthermore, the HET-CAM model evidenced robust tissue bioadhesion and anchoring without inducing microvasculature collapse, corroborating the high viability and spreading of L929 fibroblasts. These properties interact synergistically with the intrinsic osteoinductive and potential antimicrobial properties of the magnetic phase reported in the literature. In conclusion, the proposed modification demonstrates potential, yielding promising biocomposites for advanced biomedical applications.